Customise any site. For yourself, or for your AI.

Two small files change what a website does for you. UserScripts reshape the page; AgentScripts give your AI agent real tools on it. Both run in your browser, both are reversible, both are versioned, both are local-first. The Knowledge Base covers what they are, how they're built, and how they fit together.

What are AgentScripts?

User-built WebMCP tools your AI agent discovers and calls through navigator.modelContext. AgentScripts install like UserScripts and run inside your authenticated browser session, so the agent gains typed, consent-gated tools on any site you already use, without per-site API keys or headless browsers.

What are UserScripts?

The standard UserScript format: a metadata header (@match, @grant, @require, @namespace) plus a body of JavaScript. UserScripts have been around since Greasemonkey in 2004. Customaise's AI editor collapses the hour of handwritten JavaScript into a sentence in your own words.

The marketplace, for your AI agent

How AI agents discover Customaise marketplace scripts. WebMCP page-side tools, the IDE connection path, and the trust ceremony that gates every install. Useful if you are building an agent that needs to act on real websites.